Storing the gas from making charcoal

have you ever thought of captering the flamable woodgas from the retort and saving it for later use. Or vent out the top and flare the gases. When the flare auto stops the pyrolisatiom should be complete. Close the valve to the flare and your retort can cool in comfort, air tight. I have used this method several times, but on a much smaller scale. Also when the retort is closed at the end I remove it from the heat. Mine was a 5 gl. metal pail and lid that I attached a pipe and ball valve and flare then set it in a charcoal grill Wood fired fan asissted . I live right downtown Croswell Mi. No open fires on mainstreet!! Ha ha always a way around limitations. Sometimes we have to play by their rules


I think many people have thought of that, and some have even done it, but the counter argument seems compelling. A large component of wood gas is carbon monoxide a leak could be fatal. Also, the since a large part of wood gas is nitrogen and carbon dioxide, so you’d need a large tank to store a little usable gas.

Jesse, scale plays a big role in this. Yes you can make 5 gallons at a time, size it by hand, invest free time into the “perfect” system but it would be very difficult to create anything above fun hobby level without bankrupting your budget of money and time. For me everything I build I try to make Bobo proof and with minimal labour inputs or else I know it will stay dormant in the project pile. So valves, tanks,storage, pumps all that is off the table regardless of efficiency loss. Depends on your goals…
Best regards David Baillie


I have in the past made and stored hydrogen in a king sized air mattress. The mattress was kept outside and planks and weight were used to creat pressure. The use of a flashback arrestor is highly recommended. There is a guy on youtube that cooks wood on the stovetop and collects the gas in an air mattress then pumps it into a propane tank. Haven’t done that yet, need a bigger compressor.

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just my thoughts. You have to do what works for you. Limited income, 3 kids at home, still in school . Not a lot to work with after the bills are paid. So I have to find a way that moves me closer to freedom. Making woodgas to run a generator to charge batteries so that I can unplug from the grid. The cost of the batteries and generator etc will be recouped in 1-2 yrs. the thougjt of only paying basic hookup fees for utilities.

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My Memory is dim on this point, but I believe that I remember reading that there is some compelling reason why wood gas cannot be compressed and stored (or, if it is, the allowed pressure is so low that you can’t store it densely enough to help yourself much). Maybe someone else can chime in on this.

There must be a reason that “town gas” “producer gas” etc. etc. (all basically the same thing) were produced and distributed without storing the gas.

Also, as many others have pointed out on this forum, wood is already a great way to “store” woodgas in its natural state, so why would you want to complicate your life?

Based on my limited experience, it appears to me that making a wood or charcoal gasifier to run a generator to charge batteries as a supplement to solar charging is a very practical, reasonable, and achievable goal.


I’m no expert here on chemistry, but if I understand correctly what I have read that woodgas when compressed very quickly breaks down chemically to unburnable state. Also since it does not compress down to a liquid form like propane does, You can’t get enough volume into a tank to do you much good.


They stored it in ‘gasometers’ you can still see the skeletons of these monsters in some old cities. I think they even converted some brick gasometers in England to massive housing complexes. This was low pressure storage, and I think it’s main purpose was to provide a buffer between the production and demand so a sudden spike in demand didn’t overwhelm the system.


@Chris could we please split the “not-actually-about-making-charcoal-efficiently” stuff into “Storing Woodgas, The 5th”? :stuck_out_tongue: thanks. :slight_smile:


I did a little looking on the Internet. Apparently, high purity industrial CO can be stored at pressures up to 2000 PSI.

But, like Andy, I am vaguely remembering that wood gas breaks down or something when stored at pressure. So it might have something to do with the other volatiles in wood gas.

At least for gasifier produced CO, it appears that the main limitation is the fact that it has so much nitrogen in it, making pressurized storage impractical.

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More about temperature than pressure. Time is also a factor.


I take it back

I am really scratching my head on this one. I am quite sure that I remember reading an article a few years ago that stated rather definitely that attempting to compress and store wood gas was (1) dangerous, (2) led to chemical breakdown of the gas, and (3) was impractical.

But there are people out there that are studying this, and who have done it with comparatively simple apparatus (e.g. - off the shelf air compressors).

Here is a simple and well written article that describes one such study.

So far, it looks like the experiments have been done at pretty low pressures (100 to 200 PSI), but they appear to be working.

Whether it is economic to do this or not is another question.

Anyway, I don’t have any particular desire to compress wood gas since it appears to me that the gas is already efficiently stored in the wood.

However, it is interesting to know whether or not it can be done, from a scientific perspective.


I am more intrigued by the pumping/compressing of woodgas than the storing of it. Compressing just a small amount over atmospheric pressure would seem to negate the sucking losses of an internal combustion engine needed to make a gasifier work.


The reason I liked the " idea" of compressing or storing woodgas
Would be so that I could cook with it inside my aptmt kitchen I could hook it up to a mantle lantern for lights in a power out

Interesting topic. As mentioned, this is a reprise of other threads. It seems to be one of the difficulties of discussion threads, they can be hard to find once they have gone dormant, and there’s a lot of ideas and discussion on this forum.

My 2 ¢…

In a previous thread it’s been mentioned that there’s a YouTube video, titled “Stored homemade natural wood gas”, where the fellow demonstrates long term storage of compressed wood gas, at fairly low pressure.

From what I have read, and probably corroborated by what Chris has posted, though theoretically carbon monoxide degrades, at lower pressures and ambient temperatures, that probably isn’t a significant factor.

Regarding Cory’s mention of nitrogen being a dilutant, if this is retort gas we are talking about, it’s a different animal in composition, being the decomposition products of heated wood, having a distinct, and more energetic composition. Granted, a good part of the energy from retort gas will likely be in the form of tars, unless they can be catalyzed, or they may be best condensed and collected as so called “biocrude”.

Carbon monoxide isn’t efficiently compressed, and neither is methane, another component of retort and gasifier gas. It’s a losing proposition to put energy into compressing such a gas.

The engineers who set up town gas systems in the Victorian era did it right, high volume, low pressure storage.

David votes for direct use, and the simplicity of that approach. I feel that stationary power, and possibly water heating etc might be a significant niche for gas storage. To me it seems attractive to have a reliable fuel supply on tap for things that propane would be good for, occasional intermittent use, or with enough volume, even many hours of generator running.

If a person is making charcoal, there will be significant waste energy, my intuition figures that one barrel of wood in a retort might produce enough gas to pyrolize 2 barrels. If a person is involved in making charcoal, this is a major wasted potential energy source, so it’s really a different mindset and approach from direct wood gasification.

My vision: high volume, low pressure storage. Ideally, a gas bag inside a rigid container, like a grain bin, or silage silo, same system as the old gasometers, deck floating on top of the bag to provide the 2 or 3 psi. Smaller scale would have some utility, but if pyrolizing barrel volumes of wood, large volumes of not very energy dense gas would result.

Any indoor use calls for a good CO meter (or two), a lot of caution, and working to a gas fitters standards.


Garry Tait, Manitoba


I’m sorry, but this violates an important safety rule.


CO poisoning is no joke. This is odorless tasteless gas, without the safety odorant to warn you of a leak.


This is related to the DIY steam boiler rule…



Agreed. CO inside a habitation is potentially deadly, storing it there in compressed form frighteningly dangerous. However, up till the '50s, town gas was piped into homes everywhere, people were aware and accepting of the risks, though there were deaths. Today people are still killed by natural gas, but we have cultural acceptance. In the north steam used to be the preferred method of heating, but that has been passed by due to safety and licensing issues.

CO can also cause brain damage and heart muscle damage at lower levels over time.

Perhaps Jesse would be safer to look into biogas for modest lighting / other needs.


I know I know co is very deadly uncented oderless gas it was just a thought (bad thought) when I first moved into this apt. the furnace was faulty and I kept getting terrible headaches so I installed 6 co detectors in my 2bdrm apt. they never went off. all 6 tested out as in good working condition. I shut the furnace off turned the natural gas to it off. I heat with electric heaters (not cheap)
I did look into and did set up a bio digester for the production of methane gas but I live in the thumb of Mi. it does not get hot enough here where I live to operate effeicently. Will not make methane below 90F. I still have 25 gals. of bio-fertaliser to get rid of
so to set everyone’s mind at ease no I am not going to use co inside my house
I did build a hydrogen stove that worked pretty good but my bridge rectifier burnt and I repurposed the parts to the stove for another project
220vac bridge rectified gives you about 300 volts dc at 30 amps on a pwm makes a lot of hydrogen, and oxegen. for on demand use.


Many of the “Mennonites” I know around here have an elegant solution to this problem. It’s what they call a “summer kitchen” (also known as a woodstove on the back porch). I don’t see why you couldn’t do the same with a woodgas stove.

As to lighting, I have to think you are better off with solar and LED lights these days. A tiny solar PV system will light your house up like new york.


Were they just CO detectors or combo “CO/Flammable Gas” detectors? If they were just CO, then maybe you had a gas leak that was causing the headaches.

Also, where were they placed? Both CO and propane are heavier than air so they settle near the ground. Many people (including several “professionals”) seem to put CO detectors on the ceiling like smoke detectors.

Methane/natural gas is lighter-than-air so it would float to the ceiling.

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